1. offspring of the union between Olive Oil and Popeye, usually wrapped in swaddling and causes anxiety for the lucky parents
2. Lesbian term of endearment
3. glass of mother nature's finest served straight from the tap for those that enjoy the hot yellow beverage, whether deserved or not, figurative or literal

1. Popeye! Sweet Pea's about to fall from that girder on the construction site! Save him!
2. My gorgeous Sweet Pea. I could just eat you up!
3. Do you drink your own piss?

"Sweet Peas" was a phrase created by Chelsea Murphy and Andjelija Jancic. It is used as a replacement for the phrase "Cool Beans" and therefore has generally the same meaning. It's just a clever way to say cool, sweet, awesome etc.